Air Flow Measurement

[kleenair at ix.netcom.com]

Thor Johnson wrote:
> What's wrong with speed-density?  And what exactly do you do to it?  I
> thought it was just found by Air=K*MAP*RPM (where K is a magic constant),
> but I'm naive.  Am I going to get into trouble using this?


There is nothing wrong with speed-density, especially if you are not worried about emissions certification.  
But I don't know if K can be a magic CONSTANT.  Generally there is a volumetric efficiency table that is a 
function of MAP and RPM, which gives you the percentage of maximum static air flow calculation, which is 
Displacement * RPM /2 * units correction factor.  The throttle position input, along with MAP and BAP can be 
used for air flow measurement also, and its also a good way to verify if either TPS or MAP sensor readings as a 
diagnostics method.